Substituted naphthopyrans

ABSTRACT

Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds having certain substituents at the number 5 carbon atom of the naphtho portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 6, 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

DESCRIPTION OF THE INVENTION

The present invention relates to certain novel naphthopyran compounds.More particularly, this invention relates to novel photochromicnaphthopyran compounds and to compositions and articles containing suchnovel naphthopyran compounds. When exposed to light radiation involvingultraviolet rays, such as the ultraviolet radiation in sunlight or thelight of a mercury lamp, many photochromic compounds exhibit areversible change in color. When the ultraviolet radiation isdiscontinue, such a photochromic compound will return to its originalcolor or colorless state.

Various classes of photochromic compounds have been synthesized andsuggested for use in applications in which a sunlight-induced reversiblecolor change or darkening is desired. U.S. Pat. No. 3,567,605 (Becker)describes a series of pyran derivatives, including certain benzopyransand naphthopyrans. These compounds are described as derivatives ofchromene and are reported to undergo a color change, e.g., fromcolorless to yellow-orange, on irradiation by ultraviolet light attemperatures below about -30° C. Irradiation of the compounds withvisible light or upon raising the temperature to above about 0° C. isreported to reverse the coloration to a colorless state.

U.S. Pat. No. 5,066,818 describes various3,3-diaryl-3H-naphtho[2,1-b]pyrans as having desirable photochromicproperties, i.e., high colorability and acceptable fade, for ophthalmicand other applications. Also disclosed by way of comparative example inthe '818 patent are the isomeric 2,2-diaryl-2H-naphtho[1,2-b]pyrans,which are reported to require unacceptably long periods of time to fadeafter activation.

U.S. Pat. No. 3,627,690 describes photochromic2,2-di-substituted-2H-naphtho[1,2-b]pyran compositions containing minoramounts of either a base or weak-to-moderate strength acid. The additionof either an acid or base to the naphthopyran composition is reported toincrease the fade rate of the colored naphthopyrans, thereby making themuseful in eye protection applications such as sunglasses. It is reportedtherein further that the fade rate of 2H-naphtho-[1,2-b]pyrans withoutthe aforementioned additives ranges from several hours to many days toreach complete reversion. U.S. Pat. No. 4,818,096 discloses a bluecoloring photochromic benzo- or naphthopyran having at the positionalpha to the oxygen of the pyran ring a phenyl group having a nitrogencontaining substituent in the ortho or para positions.

The present invention relates to novel substituted2H-naphtho[1,2-b]pyran compounds which have been unexpectedly found tohave an acceptable fade rate in addition to a high activated intensityand a high coloration rate. In particular, the use of certainsubstituents at the 5-position of the naphtho-portion of thenaphthopyran compound increases the fade rate without the addition ofacids or bases. In addition, these compounds have certain substituentsat the 2-position of the pyran ring. Certain substituents may also bepresent at the number 6, 7, 8, 9 or 10 carbon atoms of the naphthoportion of the naphthopyran.

DETAILED DESCRIPTION OF THE INVENTION

In recent years, photochromic plastic materials, particularly plasticmaterials for optical applications, have been the subject ofconsiderable attention. In particular, photochromic ophthalmic plasticlenses have been investigated because of the weight advantage theyoffer, vis-a-vis, glass lenses. Moreover, photochromic transparenciesfor vehicles, such as cars and airplanes, have been of interest becauseof the potential safety features that such transparencies offer.

In accordance with the present invention, it has now been discoveredthat certain novel 2H-naphtho[1,2-b]pyran compounds having an acceptablefade rate, high activated intensity and a high coloration rate may beprepared. These compounds may be described as naphthopyrans havingcertain substituents at the 2 position of the pyran ring and at thenumber 5 carbon atom of the naphtho- portion of the naphthopyran ring.Certain substituents may also be present at the 6, 7, 8, 9 or 10 carbonatoms of the naphtho portion of the naphthopyran ring. These compoundsmay be represented by the following graphic formula: ##STR1##

In graphic formula I, R₁ may be the group, --CH₂ X or --C(O)Y, X may behalogen, hydroxy, benzoyloxy, C₁ -C₆ alkoxy, C₂ -C₆ acyloxy, amino, C₁-C₆ mono-alkylamino, C₁ -C₆ dialkylamino, i.e., di(C₁ -C₆) alkylamino,morpholino, piperidino, 1-indolinyl, pyrrolidyl, trimethylsilyloxy, orthe group, --OCH(R₁₁)Z; Y may be the group, --OCH(R₁₁)Z or anunsubstituted, mono-substituted, or di-substituted heterocyclic ringselected from the group consisting of 1-indolinyl, morpholino,piperidino, 1-pyrrolidyl, 1-imidazolidyl, 2-imidazolin-1-yl,pyrazolidyl, pyrazolinyl and 1-piperazinyl; Z being --CN, --CF₃,halogen, --C(O)R₁₂, or COOR₁₂ ; R₁₁ may be hydrogen or C₁ -C₆ alkyl; theheterocyclic ring substituents may be C₁ -C₆ alkyl or C₁ -C₆ alkoxy, andhalogen may be chloro or fluoro.

Preferably, R₁ is the group, --CH₂ X or --C(O)Y, wherein X is hydroxy,C₁ -C₄ alkoxy, or C₂ -C₄ acyloxy, Y is the group, --OCH(R₁₁)Z, or anunsubstituted or mono-substituted heterocyclic ring selected from thegroup consisting of 1-indolinyl, morpholino, piperidino, and1-pyrrolidyl, wherein Z is --CN, --C(O)R₁₂, or --COOR₁₂, R₁₁ and R₁₂ areis hydrogen or C₁ -C₄ alkyl; and the heterocyclic ring substituents areC₁ -C₄ alkyl or C₁ -C₄ alkoxy.

More preferably, R₁ is the group, --CH₂ X, or --C(O)Y, wherein X ishydroxy, C₁ -C₄ alkoxy, or C₂ -C₄ acyloxy and Y is an unsubstituted ormono-substituted heterocyclic ring selected from the group consisting of1-indolinyl, morpholino, and piperidino. Most preferably, R₁ ishydroxymethyl, acetoxymethyl, morpholinocarbonyl, or piperidinocarbonyl.

R₂ and each R₃ in graphic formula I may be hydrogen, C₁ -C₆ alkyl, C₃-C₇ cycloalkyl, unsubstituted, mono-, di-, or tri-substituted phenyl,the group, --OR₆, wherein R₆ may be hydrogen, (C₁ -C₆)alkyl, phenyl(C₁-C₃)alkyl, mono-substituted phenyl(C₁ -C₃)alkyl, (C₁ -C₆)alkoxy(C₂-C₄)alkyl, C₃ -C₇ cycloalkyl, mono(C₁ -C₄)alkyl substituted C₃ -C₇cycloalkyl, C₁ -C₆ haloalkyl, allyl, the group, --CH(R₇)W, wherein W maybe --CN, --CF₃, halogen, --C(O)R₇, or --COOR₇, wherein R₇ may behydrogen, C₁ -C₆ alkyl, or (C₁ -C₆)alkoxy(C₂ -C₄)alkyl, or R₆ may be thegroup, --C(O)T, wherein T may be hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy,the substituted or unsubstituted aryl groups phenyl or naphthyl,phenoxy, C₁ -C₆ mono-or di-alkyl substituted phenoxy, C₁ -C₆ mono-ordi-alkoxy substituted phenoxy, C₁ -C₆ mono-or di- alkoxy substitutedphenylamino, each of said phenyl or naphthyl substituents being C₁ -C₆alkyl, C₁ -C₆ alkoxy or halogen, each of said halogen or halosubstituents being chloro or fluoro, and n is selected from the integers0, 1, 2, and 3.

Preferably, R₂ and each R₃ are hydrogen, C₁ -C₄ alkyl, unsubstituted,mono-, di-, or tri-substituted phenyl, the group, --OR₆, wherein R₆ isC₁ -C₄ alkyl or the group, --CH(R₇)W, wherein W is --COOR₇, and R₇ ishydrogen or C₁ -C₄ alkyl, the phenyl substituents are C₁ -C₄ alkyl, C₁-C₄ alkoxy or fluoro and n is selected from the integers 0, 1 and 2.

More preferably, R₂ and each R₃ are hydrogen, C₁ -C₂ alkyl,unsubstituted, mono-, di-, or tri-substituted phenyl, the group, --OR₆,wherein R₆ is C₁ -C₂ alkyl or the group, --CH(R₇)W, wherein W is--COOR₇, and R₇ is C₁ -C₂ alkyl, the phenyl substituents are C₁ -C₂alkyl, C₁ -C₂ alkoxy or fluoro, and n is selected from the integers 0, 1and 2. Most preferably, R₂ and each R₃ are hydrogen, phenyl, methoxy,methyl or fluoro.

In graphic formula I, B and B' may each be selected from the groupconsisting of: (i) the unsubstituted, mono-, di-, and tri-substitutedaryl groups phenyl and naphthyl; (ii) the unsubstituted, mono- anddi-substituted heterocyclic aromatic groups pyridyl, furanyl,benzofuran-2-yl, benzofuran-3-yl, thienyl, benzothien-2-yl,benzothien-3-yl, dibenzothienyl, dibenzofuranyl, and carbazolyl, thearyl and heterocyclic substituents being selected from the groupconsisting of hydroxy, amino, C₁ -C₆ monoalkylamino, C₁ -C₆dialkylamino, morpholino, piperidino, 1-indolinyl, pyrrolidyl,1-imidazolidyl, 2-imidazolin-1-yl, 2-pyrazolidyl, pyrazolinyl,1-piperazinyl, C₁ -C₆ alkyl, C₁ -C₆ haloalkyl, C₁ -C₆ alkoxy, mono(C₁-C₆)alkoxy(C₁ -C₄)alkyl, acryloxy, methacryloxy, and halogen, whereinthe halogen or (halo) group may be fluoro or chloro; (iii) the groupsrepresented by the following graphic formulae II A and II B: ##STR2##wherein D may be carbon or oxygen and E may be oxygen or substitutednitrogen, provided that when E is substituted nitrogen, D is carbon,said nitrogen substituent being selected from the group consisting ofhydrogen, C₁ -C₆ alkyl and C₂ -C₆ acyl; each R₈ may be C₁ -C₆ alkyl, C₁-C₆ alkoxy, hydroxy or halogen, wherein the halogen may be chloro orfluoro; R₉ and R₁₀ may each be hydrogen or C₁ -C₆ alkyl; and m may bethe integer 0, 1, or 2; (iv) C₁ -C₆ alkyl, C₁ -C₆ haloalkyl, C₁ -C₆alkoxy(C₁ -C₄)alkyl, C₃ -C₆ cycloalkyl, mono(C₁ -C₆) alkoxy(C₃-C₆)cycloalkyl, mono(C₁ -C₆)alkyl-(C₃ -C₆)cycloalkyl, and halo (C₃-C₆)cycloalkyl, said halo groups being fluoro or chloro; and (v) thegroup represented by the following graphic formula II C: ##STR3##wherein U may be hydrogen or C₁ -C₄ alkyl, and V may be selected fromthe unsubstituted, mono- and di-substituted members of the groupconsisting of naphthyl, phenyl, furanyl, and thienyl, wherein thesubstituents for each member of said group are C₁ -C₄ alkyl, C₁ -C₄alkoxy, fluoro, or chloro; or (vi) B and B' taken together may form anunsubstituted, mono- or di-substituted fluoren-9-ylidene or form amember selected from the group consisting of saturated C₃ -C₁₂spiro-monocyclic hydrocarbon rings, e.g., cyclopropylidene,cyclobutylidene, cyclopentylidene, cyclohexylidene, cycloheptylidene,cyclooctylidene, cyclononylidene, cyclodecylidene, cycloundecylidene,cyclododecylidene, saturated C₇ -C₁₂ spiro-bicyclic hydrocarbon rings,e.g., bicyclo[2.2.1]heptylidene, i.e., norbornylidene, 1,7,7-trimethylbicyclo[2.2.1]heptylidene, i.e., bornylidene, bicyclo[3.2.1]octylidene,bicyclo[3.3.1]nonan-9-ylidene, bicyclo[4.3.2]undecane, and saturated C₇-C₁₂ spiro-tricyclic hydrocarbon rings, e.g., tricyclo[2.2.1.0²,6]heptylidene, tricyclo[5.3.1.1²,6 ]dodecylidene, and tricyclo[3.3.1.1³,7]decylidene, i.e., adamantylidene, wherein the fluoren-9-ylidenesubstituents may be selected from the group consisting of C₁ -C₄ alkyl,C₁ -C₄ alkoxy, fluoro and chloro.

Preferably, B and B' are each selected from the group consisting of: (i)unsubstituted, mono-, di- and tri-substituted phenyl; (ii) theunsubstituted, mono- and di-substituted heterocyclic aromatic groupspyridyl, furanyl, benzofuran-2-yl, benzofuran-3-yl, thienyl,benzothien-2-yl, benzothien-3-yl, dibenzothienyl, dibenzofuranyl andcarbazolyl, each of the phenyl and heterocyclic substituents beingselected from the group consisting of morpholino, piperidino, C₁ -C₄alkyl, C₁ -C₄ alkoxy and halogen, the halogen or (halo) group beingfluoro or chloro; (iii) the groups represented by the graphic formula IIA, wherein D is carbon and E is oxygen; each R₈ is C₁ -C₄ alkyl, C₁ -C₄alkoxy, hydroxy or halogen, the halogen being chloro or fluoro; R₉ andR₁₀ are each hydrogen or C₁ -C₄ alkyl; and m is the integer 0, 1 or 2;(iv) C₁ -C₄ alkyl, C₁ -C₆ alkoxy(C₁ -C₄)alkyl and C₃ -C₆ cycloalkyl; and(v) the group represented by graphic formula II C, wherein U is hydrogenor methyl, and V is phenyl or mono-substituted phenyl, the phenylsubstituent being C₁ -C₄ alkyl, C₁ -C₄ alkoxy or fluoro; or (vi) B andB' taken together form an unsubstituted or mono-substitutedfluoren-9-ylidene or a member selected from the group consisting ofsaturated C₃ -C₈ spiro-monocyclic hydrocarbon rings, saturated C₇ -C₁₀spiro-bicyclic hydrocarbon ring, and saturated C₇ -C₁₀ spiro-tricyclichydrocarbon rings.

More preferably, B and B' are each selected from the group consistingof: (i) unsubstituted, mono- and di-substituted phenyl; (ii) theunsubstituted, mono- and di-substituted heterocyclic aromatic groupspyridyl, benzofuran-2-yl, benzothien-2-yl, dibenzothienyl anddibenzofuranyl, each of the phenyl and heterocyclic substituents beingselected from the group consisting of morpholino, piperidino, C₁ -C₂alkyl and C₁ -C₂ alkoxy; and (iii) the groups represented by graphicformula II A, wherein D is carbon and E is oxygen; each R₈ is C₁ -C₂alkyl, C₁ -C₂ alkoxy or fluoro; R₉ and R₁₀ are each hydrogen or C₁ -C₂alkyl; and m is the integer 0, 1 or 2; or (iv) B and B' taken togetherform fluoren-9-ylidene, bornylidene, norbornylidene,bicyclo[3.3.1]nonan-9-ylidene or adamantylidene. Most preferably, B andB' are each phenyl, methoxy substituted phenyl, morpholino substitutedphenyl, dibenzofuran-2-yl, or 2,3-dihydrobenzofuran-5-yl.

Compounds represented by graphic formula I may be prepared by thefollowing steps. Benzophenones represented by graphic formula V and VAare either purchased or prepared by Friedel-Crafts methods using anappropriately substituted or unsubstituted benzoyl chloride of graphicformula IV and a commercially available substituted or unsubstitutedbenzene compound of graphic formula III. See the publicationFriedel-Crafts and Related Reactions, George A. Olah, IntersciencePublishers, 1964, Vol. 3, Chapter XXXI (Aromatic Ketone Synthesis), and"Regioselective Friedel-Crafts Acylation of 1,2,3,4-Tetrahydroquinolineand Related Nitrogen Heterocycles: Effect on NH Protective Groups andRing Size" by Ishihara, Yugi et al, J. Chem. Soc., Perkin Trans. 1,pages 3401 to 3406, 1992.

The compounds represented by graphic formulae III and IV are dissolvedin a solvent, such as carbon disulfide or methylene chloride, andreacted in the presence of a Lewis acid, such as aluminum chloride ortin tetrachloride, to form the corresponding substituted benzophenonerepresented by graphic formula V (or VA in Reaction B). R and R'represent potential phenyl substituents.

REACTION A ##STR4##

In Reaction B, the substituted or unsubstituted ketone represented bygraphic formula VA, in which B and B' may represent groups other thansubstituted or unsubstituted phenyl, is reacted with sodium acetylide ina suitable solvent, such as anhydrous tetrahydrofuran (THF), to form thecorresponding propargyl alcohol represented by graphic formula VI.Propargyl alcohols having B or B' groups other than substituted andunsubstituted phenyl may be prepared from commercially available ketonesor for example, from ketones prepared via reaction of an acyl halidewith a substituted or unsubstituted benzene, naphthalene, orheteroaromatic compound. Propargyl alcohols having B or B' groupsrepresented by graphic formula II C may be prepared by the methodsdescribed in U.S. Pat. No. 5,274,132, column 2, lines 40 to 68.

REACTION B ##STR5##

Naphthols represented by graphic formulae VIII and XIII, used in thepreparation of naphthopyrans of graphic formula I, may be prepared asdescribed in Reaction C or D. In Reaction C, 1,4-dihydroxy-2-naphthoicacid, represented by graphic formula VII, is reacted with an alkylhalide, e.g., methyl iodide, in the presence of ethyldiisopropyl aminein a suitable solvent such as anhydrous dimethylformamide (DMF), to formthe corresponding methyl-1,4-dihydroxy-2-naphthoate, which isrepresented by graphic formula VIII. This reaction is further describedin The Journal of Organic Chemistry, 46(17), 1981, page 3477.

REACTION C ##STR6##

In Reaction D, a substituted or unsubstituted acetophenone,benzophenone, or benzaldehyde represented by graphic formula IX isreacted with dimethyl succinate (graphic formula X) in the presence of abase such as sodium hydride or potassium t-butoxide in a suitablesolvent such as toluene or THF to form the appropriate substitutedmonoester of an α-arylidene succinic acid, represented by graphicformula XI. Compound XI is heated with acetic anhydride and anhydroussodium acetate to form the corresponding acetate derivative representedby the graphic formula XII. Compound XII is reacted with hydrochloricacid and an anhydrous alcohol such as anhydrous methanol to form thecorresponding naphthol, represented by graphic formula XIII. Reaction Dis further described in the text Organic Reactions, Vol. VI, Chapter 1,pages 1-73, John Wiley & Sons, Inc., New York.

REACTION D ##STR7##

In Reaction E, a propargyl alcohol represented by graphic formula VI iscoupled with a naphthol represented by graphic formula VIIIA (VIIIfurther substituted with (R₃)_(n)) to form 6-hydroxy naphthopyransrepresented by graphic formula XIV. The 6-hydroxy substituent ofcompounds represented by graphic formula XIV may be converted, forexample to a 6-alkoxy group, by reaction with an alkyl halide, e.g.,methyl iodide, ethyl iodide, benzyl bromide, etc., to form compoundsrepresented by graphic formula XV. Compounds represented by graphicformula XV may be reduced, for example with lithium aluminum hydride(LAH) in an inert solvent such as THF to yield the 5-hydroxymethylsubstituted compounds represented by graphic formula XVI. The5-hydroxymethyl substituent of compounds represented by graphic formulaXVI may be derivatized in a variety of ways. It can be converted to analkoxymethyl by reacting compounds represented by graphic formula XVIwith an alkyl halide such as methyl iodide, n-propyl bromide, benzylbromide, etc., in the presence of a base such as potassium carbonate toproduce compounds represented by graphic formula XVII. Alternatively thehydroxymethyl can be acylated with an acyl halide, e.g. acetyl chloride,benzoyl chloride, etc., to yield compounds represented by graphicformula XVIII. In a third example, the hydroxymethyl may be reacted withtrimethylsilyl chloride, in the presence of an acid acceptor, e.g.,triethyl amine, to produce trimethylsilyl ethers represented bycompounds of graphic formula XIX.

REACTION E ##STR8##

In Reaction F, a propargyl alcohol represented by graphic formula VI iscoupled with a naphthol represented by graphic formula XIII to form6-aryl, 6-alkyl, or 6-hydrogen bearing naphthopyran compoundsrepresented by graphic formula XX. Compounds represented by graphicformula XX may be reduced, for example with lithium aluminum hydride(LAH) in an inert solvent such as THF to give 5-hydroxymethyl compoundsrepresented by graphic formula XXI. The 5-hydroxymethyl substituent ofcompounds represented by graphic formula XXI may be derivatized in avariety of ways. It can be converted to a chloromethyl group by reactingcompounds represented by graphic formula XXI with thionyl chloride toproduce compounds represented by graphic formula XXII. The5-chloromethyl of compounds represented by graphic formula XXII can befurther derivatized using reactions known in the art, such as byreacting it with a primary, secondary, or heterocyclic amine, e.g.propyl amine, diethyl amine, morpholine, etc., to give 5-aminomethylcompounds represented by formula XXIII. Alternatively the hydroxymethylgroup of compounds represented by graphic formula XXI can be reactedwith an alkyl halide, e.g. methyl iodide, propyl iodide, benzyl bromide,etc., to yield compounds represented by graphic formula XXIV.

REACTION F ##STR9##

Compounds with an amide group substituted in the 5-position are preparedby the series of reactions found in Reaction G. Naphthols represented bygraphic formula XIII are hydrolyzed to carboxynaphthols represented byformula XXV using potassium hydroxide dissolved in a mixture of waterand alcohol. The free hydroxy substituent of compounds of graphicformula XXV is protected by reaction with acetyl chloride to yieldacetoxy substituted compounds of graphic formula XXVI. The carboxysubstituent of compounds of graphic formula XXVI is converted to an acidchloride by reaction with thionyl chloride to yield compounds of graphicformula XXVII. The acid chloride of compounds of graphic formula XXVIIis converted to an amide group by reaction with a primary, secondary orheterocyclic amine, e.g. propyl amine, diethyl amine, morpholine,piperidine, etc., to give compounds of graphic formula XXVIII. Theacetoxy substituent of compounds of graphic formula XXVIII isdeprotected by reaction with methanol in the presence of HCl to yieldthe naphthols of graphic formula XXIX. Pyrans containing a 5-amide grouprepresented by graphic formula XXX are prepared by reacting a naphtholof graphic formula XXIX with a propargyl alcohol of graphic formula VI.

REACTION G ##STR10##

Compounds represented by graphic formula I may be used in thoseapplications in which organic photochromic substances may be employed,such as optical lenses, e.g., vision correcting ophthalmic lenses andplano lenses, face shields, goggles, visors, camera lenses, windows,automotive windshields, aircraft and automotive transparencies, e.g.,T-roofs, sidelights and backlights, plastic films and sheets, textilesand coatings, e.g., coating compositions such as paints, andverification marks on security documents, e.g., documents such asbanknotes, passports and drivers' licenses for which authentication orverification of authenticity may be desired. Naphthopyrans representedby graphic formula I exhibit color changes from colorless to colorsranging from yellow to red/purple.

Examples of contemplated naphthopyrans within the scope of the inventionare the following of:

(a) 2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran;

(b) 2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-phenyl-2H-naphtho[1,2-b]pyran;

(c) 2,2-bis (4-methoxyphenyl)-5-acetoxymethyl-6-phenyl-2H -naphtho[1,2-b]pyran;

(d)2-(4-methoxyphenyl)-2-(2,3-dihydrobenzofuran-5-yl)-5-piperidinocarbonyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran;

(e)2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-methoxy-2H-naphtho[1,2-b]pyran;

(f) 2,2-diphenyl-5-methoxymethyl-6-methoxy-2H -naphtho[1,2-b]pyran;

(g) 2,2-spiroadamantylene-5-acetoxymethyl-6-methoxy-2H-naphtho[1,2-b]pyran;

(h) 2,2-bis(4-methoxyphenyl)-5-trimethylsilyloxymethyl-6-methoxy-2H-naphtho[1,2 -b]pyran;

(i)2-(4-methoxyphenyl)-2-t-butyl-5-methoxymethyl-6-phenyl-9-methoxy-2H-naphtho[1,2-b]pyran;and

(j)2-(4-methoxyphenyl)-2-(2,3-dihydrobenzofuran-5-yl)-5-chloromethyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran.

It is contemplated that the organic photochromic naphthopyrans ofgraphic formula I be used in combination with other appropriatecomplementary organic photochromic materials so that together theyproduce a near neutral gray or brown color shade when the plastic lenscontaining such photochromic materials are exposed to ultraviolet light.For example, a compound which colors to yellow may be blended with acompound that colors to an appropriate purple to produce a brown shade.Similarly, a compound which is orange in its colored state will producea shade of gray when used in conjunction with an appropriate bluecoloring compound. The aforesaid described combination of photochromicmaterials may be used also in applications other than ophthalmic lenses.

The novel naphthopyran compounds of the present invention, such as thoseheretofore described, may be used alone or in combination withcomplementary photochromic compounds, i.e., organic photochromiccompounds having at least one activated absorption maxima within therange of between about 400 and 700 nanometers, or substances containingsame, and may be incorporated, e.g., dissolved or dispersed, in apolymeric organic host material used to prepare photochromic articlesand which compounds or mixtures of compounds color when activated to anappropriate hue.

A first group of complementary organic photochromic substancescontemplated for use with the organic photochromic naphthopyrans of thepresent invention are those having an activated absorption maximumwithin the visible range of greater than 570 nanometers, e.g., betweenabout greater than 570 to 700 nanometers. These materials typicallyexhibit a blue, blueish-green, or blueish-purple color when exposed toultraviolet light in an appropriate solvent or matrix. Many of suchcompounds are described in the open literature. For example,spiro(indoline)naphthoxazines have been described, among others, in U.S.Pat. Nos. 3,562,172; 3,578,602; 4,215,010; and 4,342,668;spiro(indoline)naphthoxazines having certain substituents on the 8' and9' positions of the naphthoxazine portion of the molecule are describedin U.S. Pat. No. 5,405,958; spiro(indoline)pyridobenzoxazines aredescribed in U.S. Pat. No. 4,637,698;spiro(benzindoline)pyridobenzoxazines andspiro(benzindoline)naphthoxazines are described in U.S. Pat. No.4,931,219; spiro(benzindoline)naphthopyrans are described in JapanesePatent Publication 62/195383; spiro(indoline)benzoxazines are describedin U.S. Pat. No. 4,816,584; spiro(indoline)benzopyrans,spiro(indoline)naphthopyrans, and spiro(indoline)quinopyrans aredescribed, for example, in U.S. Pat. No. 4,880,667; and benzopyrans andnaphthopyrans having a nitrogen-containing substituent in the 2-positionof the pyran ring are described in U.S. Pat. No. 4,818,096.Spiro(indoline)pyrans are also described in the text, Techniques inChemistry, Volume III, "Photochromism," Chapter 3, Glenn H. Brown,Editor, John Wiley and Sons, Inc., New York, 1971.

A second group of complementary organic photochromic substancescontemplated for use with the organic photochromic naphthopyrans of thepresent invention are those having at least one absorption maximumwithin the visible range of between about 400 and less than 500nanometers. These materials typically exhibit a yellow-orange color whenexposed to ultraviolet light in an appropriate solvent or matrix. Suchcompounds include certain chromenes, i.e., benzopyrans andnaphthopyrans. Many of such chromenes are described in the openliterature, e.g., U.S. Pat. Nos. 3,567,605; 4,826,977; and 5,066,818.Other examples of complementary benzopyrans and naphthopyrans that maybe used with the naphthopyrans of the present invention include: thosehaving a spiro adamantane group at the position alpha to the oxygen atomof the pyran ring, which are described in U.S. Pat. No. 4,826,977; 2H-naphtho-[1,2-b]pyran compounds having certain substitutents at thenumber 5 and 6 carbon atoms of the naphtho portion of the naphthopyranand at the 2 position of the pyran which are the subject of co-pendingU.S. patent application Ser. No. 08/164,187, filed Dec. 9, 1993;3H-naphtho[2,1-b]pyrans having at least one ortho-substituted phenylsubstituent at the 3-position of the pyran ring which are described inU.S. Pat. No. 5,066,818; 3H-naphtho[2,1-b]pyran compounds having certainsubstituents at the number 8 carbon atom and certain substituents at thenumber 7 or 9 carbon atom, all substituents being on the naphtho portionof the naphthopyran, which are the subject of co-pending U.S. patentapplication Ser. No. 08/080,246, filed Jun. 21, 1993;3H-naphtho[2,1-b]pyrans substituted at the 3 position of the pyran ringwith (i) an aryl substituent and (ii) a phenyl substituent having a 5-or 6-member heterocyclic ring fused at the number 3 and 4 carbon atomsof the phenyl substituent are described in U.S. Pat. No 5,384,077;diaryl-3H-naphtho[2,1-b]pyran compounds having a substituted orunsubstituted, 5 or 6 member heterocyclic ring fused to the g, i, or 1side of the naphthopyran which are the subject of co-pending U.S. patentapplication Ser. No.08/225,022 filed Apr. 8, 1994; naphthopyrancompounds substituted at the number 8 carbon atom on the naphtho portionof the naphthopyran ring, with for example, a methoxy group which arethe subject of U.S. Pat. No. 5,238,931; naphthopyran compounds, examplesof which are 3-aryl-3-arylalkenyl naphthopyrans, which are described inU.S. Pat. No. 5,274,132; and naphtho[2,1-b]pyrans substituted at thenumber five carbon atom with, for example, an acetoxy group, which arethe subject of U.S. Pat. No. 5,244,602.

A third group of complementary organic photochromic substancescontemplated for use with the organic photochromic naphthopyrans of thepresent invention are those having an absorption maximum within thevisible range of between about 400 to about 500 nanometers and anotherabsorption maximum within the visible range of between about 500 toabout 700 nanometers. These materials typically exhibit color(s) rangingfrom yellow to purple and yellow/brown to purple/gray when exposed toultraviolet light in an appropriate solvent or matrix. Examples of thesecompounds include certain substituted 2H-phenanthro[4,3-b]pyrans;substituted 3H -phenanthro[1,2-b]pyrans; and benzopyran compounds, suchas those having substituents at the 2-position of the pyran ring and asubstituted or unsubstituted heterocyclic ring, such as a benzothieno orbenzofurano ring fused to the benz portion of the benzopyran. Such laterdescribed compounds are the subject of co-pending U.S. patentapplication Ser. Nos. 08/286,039 filed Aug. 4, 1994 and U.S. Pat. No.5,411,679.

Photochromic articles of the present invention may contain onephotochromic compound or a mixture of photochromic compounds, as desiredor required. Individual photochromic compounds or mixtures ofphotochromic compounds may be used to attain certain activated colorssuch as neutral grays or browns.

The compounds of the present invention (hereinafter also referred to andincluded as a second group photochromic compound) may be used also incombination with the organic photochromic substances of the firstcomplementary group of photochromic compounds described herein, i.e.,those that color to colors blue, blueish-green, or blueish-purple orwith other organic photochromic substances in the aforesaid second groupof photochromic compounds. Either members of the first or second groupof photochromic compounds or mixtures of such compounds may be combinedwith or used in conjunction with the third group described herein thatexhibit colors ranging from yellow to purple and yellow/brown topurple/gray.

Each of the photochromic substances described herein may be used inamounts (or in a ratio) such that an organic host material to which thephotochromic compounds or mixture of compounds is applied or in whichthey are incorporated exhibits a desired resultant color, e.g., asubstantially neutral color when activated with unfiltered sunlight,i.e., as near a neutral color as possible given the colors of theactivated photochromic compounds.

A neutral gray color exhibits a spectrum that has relatively equalabsorption in the visible range between 400 and 700 nanometers. Aneutral brown color exhibits a spectrum in which the absorption in the400-550 nanometer range is moderately larger than in the 550-700nanometer range. An alternative way of describing color is in terms ofits chromaticity coordinates, which describe the qualities of a color inaddition to its luminance factor, i.e., its chromaticity. In the CIEsystem, the chromaticity coordinates are obtained by taking the ratiosof the tristimulus values to their sum, e.g., x=X/(X+Y+Z) andy=Y/(X+Y+Z). Color as described in the CIE system can be plotted on achromaticity diagram, usually a plot of the chromaticity coordinates xand y. See pages 47-52 of Principles of Color Technology, by F. W.Billmeyer, Jr., and Max Saltzman, Second Edition, John Wiley and Sons,N.Y. (1981). As used herein, a near neutral color is one in which thechromaticity coordinate values of "x" and "y" for the color are withinthe following ranges (D65 illuminant): x=0.260 to 0.400, y=0.280 to0.400 following activation to 40 percent luminous transmission byexposure to solar radiation (Air Mass 1 or 2).

The amount of photochromic substance or composition containing sameapplied to or incorporated into a host material is not critical providedthat a sufficient amount is used to produce a photochromic effectdiscernible to the naked eye upon activation. Generally such amount canbe described as a photochromic amount. The particular amount useddepends often upon the intensity of color desired upon irradiationthereof and upon the method used to incorporate or apply thephotochromic substances. Typically, the more photochromic substanceapplied or incorporated, the greater is the color intensity up to acertain limit.

The relative amounts of the aforesaid photochromic compounds used willvary and depend in part upon the relative intensities of the color ofthe activated species of such compounds, and the ultimate color desired.Generally, the amount of total photochromic substance incorporated intoor applied to a photochromic optical host material may range from about0.05 to about 1.0, e.g., from 0.1 to about 0.45, milligrams per squarecentimeter of surface to which the photochromic substance(s) isincorporated or applied. When mixtures of the aforedescribed organicphotochromic complementary groups are used, the weight ratio of suchmaterials, i.e., (first to second), (second to third), and (naphthopyranof the present invention to other second group compounds) will vary fromabout 1:3 to about 3:1, between about 0.75:1 and about 2:1. Thecombination of the first, second, and third described organicphotochromic complementary groups may have a weight ratio that will varyfrom about 1:3:1 to 3:1:3.

The photochromic substances of the present invention may be applied toor incorporated into a host material such as a polymeric organic hostmaterial by various methods described in the art. Such methods includedissolving or dispersing the photochromic substance within the hostmaterial, e.g., casting it in place by adding the photochromic substanceto the monomeric host material prior to polymerization; imbibition ofthe photochromic substance into the host material by immersion of thehost material in a hot solution of the photochromic substance or bythermal transfer; providing the photochromic substance as a separatelayer between adjacent layers of the host material, e.g., as a part of apolymeric film; and applying the photochromic substance as part of acoating placed on the surface of the host material. The term"imbibition" or "imbibe" is intended to mean and include permeation ofthe photochromic substance alone into the host material, solventassisted transfer of the photochromic substance into a porous polymer,vapor phase transfer, and other such transfer mechanisms.

Compatible (chemically and color-wise) tints, i.e., dyes, may be appliedto the host material to achieve a more aesthetic result, for medicalreasons, or for reasons of fashion. The particular dye selected willvary and depend on the aforesaid need and result to be achieved. In oneembodiment, the dye may be selected to complement the color resultingfrom the activated photochromic substances, e.g., to achieve a moreneutral color or absorb a particular wavelength of incident light. Inanother embodiment, the dye may be selected to provide a desired hue tothe host matrix when the photochromic substances is in an unactivatedstate.

Adjuvant materials may also be incorporated into the host material withthe photochromic substances prior to, simultaneously with or subsequentto application or incorporation of the photochromic substances in thehost material. For example, ultraviolet light absorbers may be admixedwith photochromic substances before their application to the hostmaterial or such absorbers may be superposed, e.g., superimposed, as alayer between the photochromic substance and the incident light.Further, stabilizers may be admixed with the photochromic substancesprior to their application to the host material to improve the lightfatigue resistance of the photochromic substances. Stabilizers, such ashindered amine light stabilizers and singlet oxygen quenchers, e.g., anickel ion complex with an organic ligand, are contemplated. They may beused alone or in combination. Such stabilizers are described in U.S.Pat. No. 4,720,356. Finally, appropriate protective coating(s) may beapplied to the surface of the host material. These may be abrasionresistant coatings and/or coatings that serve as oxygen barriers. Suchcoatings are known in the art.

The host material will usually be transparent, but may be translucent oreven opaque. The host material need only be transparent to that portionof the electromagnetic spectrum, which activates the photochromicsubstance, i.e., that wavelength of ultraviolet (UV) light that producesthe open form of the substance and that portion of the visible spectrumthat includes the absorption maximum wavelength of the substance in itsUV activated form, i.e., the open form. Preferably, the host colorshould not be such that it masks the color of the activated form of thephotochromic substance, i.e., so the change in color is readily apparentto the observer. More preferably, the host material article is a solidtransparent or optically clear material, e.g., materials suitable foroptical applications, such as plano and ophthalmic lenses, windows,automotive transparencies, e.g., windshields, aircraft transparencies,plastic sheeting, polymeric films, etc.

Examples of polymeric organic host materials which may be used with thephotochromic substances or compositions described herein include:polymers, i.e., homopolymers and copolymers, of polyol(allyl carbonate)monomers, diethylene glycol dimethacrylate monomers, diisopropenylbenzene monomers, and alkoxylated polyhydric alcohol acrylate monomerssuch as ethoxylated trimethylol propane triacrylate monomers; polymers,i.e., homopolymers and copolymers, of polyfunctional, i.e., mono-, di-,tri-, tetra, or multi-functional, acrylate and/or methacrylate monomers,polyacrylates, polymethacrylates, poly( C₁ -C₁₂ alkyl methacrylates)such as poly(methyl methacrylate), polyoxy(alkylene methacrylates) suchas poly(ethylene glycol bis methacrylates), poly(alkoxylated phenolmethacrylates) such as poly(ethoxylated bisphenol A dimethacrylate),cellulose acetate, cellulose triacetate, cellulose acetate propionate,cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol),poly(vinyl chloride), poly(vinylidene chloride), polyurethanes,thermoplastic polycarbonates, polyesters, poly(ethylene terephthalate),polystyrene, poly (alpha methylstyrene), copoly(styrene-methylmethacrylate), copoly(styrene-acrylonitrile), polyvinylbutyral andpolymers, i.e., homopolymers and copolymers, of diallylidenepentaerythritol, particularly copolymers with polyol (allyl carbonate)monomers, e.g., diethylene glycol bis(allyl carbonate), and acrylatemonomers.

Transparent copolymers and blends of transparent polymers are alsosuitable as host materials. Preferably, the host material is anoptically clear polymerized organic material prepared from athermoplastic polycarbonate resin, such as the carbonate-linked resinderived from bisphenol A and phosgene, which is sold under thetrademark, LEXAN; a polyester, such as the material sold under thetrademark, MYLAR; a poly(methyl methacrylate), such as the material soldunder the trademark, PLEXIGLAS; polymerizates of a polyol(allylcarbonate) monomer, especially diethylene glycol bis(allyl carbonate),which monomer is sold under the trademark CR-39, and polymerizates ofcopolymers of a polyol (allyl carbonate), e.g., diethylene glycolbis(allyl carbonate), with other copolymerizable monomeric materials,such as copolymers with vinyl acetate, e.g., copolymers of from 80-90percent diethylene glycol bis(allyl carbonate) and 10-20 percent vinylacetate, particularly 80-85 percent of the bis(allyl carbonate) and15-20 percent vinyl acetate, and copolymers with a polyurethane havingterminal diacrylate functionality, as described in U.S. Pat. No.4,360,653 and 4,994,208; and copolymers with aliphatic urethanes, theterminal portion of which contain allyl or acrylyl functional groups asdescribed in U.S. Pat. No. 5,200,483; poly(vinyl acetate),polyvinylbutyral, polyurethane, polymers of members of the groupconsisting of diethylene glycol dimethacrylate monomers, diisopropenylbenzene monomers, and ethoxylated trimethylol propane triacrylatemonomers; cellulose acetate, cellulose propionate, cellulose butyrate,cellulose acetate butyrate, polystyrene and copolymers of styrene withmethyl methacrylate, vinyl acetate and acrylonitrile. More particularly,contemplated is use of the photochromic naphthopyrans of the presentinvention with optical organic resin monomers used to produce opticallyclear polymerizates, i.e., materials suitable for optical applications,such as for example plano and ophthalmic lenses, windows, and automotivetransparencies. Such optically clear polymerizates may have a refractiveindex that may range from about 1.48 to about 1.75, e.g., from about1.495 to about 1.66.

The present invention is more particularly described in the followingexamples which are intended as illustrative only, since numerousmodifications and variations therein will be apparent to those skilledin the art.

EXAMPLE 1 STEP 1

4,4'-Dimethoxybenzophenone (0.27 mole) was dissolved in a reaction flaskcontaining 200 ml of anhydrous tetrahydrofuran saturated with acetyleneand stirred at room temperature. An 18 weight percent suspension ofsodium acetylide in xylene/mineral oil (0.3 mole of sodium acetylide)was added to the reaction flask and the mixture was stirred. Afterstirring 16 hours at room temperature under a nitrogen atmosphere, thecontents of the reaction flask mixture was added to a 5 weight percentaqueous hydrochloric acid and ice mixture. The resulting mixture wasextracted with diethyl ether. The organic layer was separated, washed,and dried over anhydrous sodium sulfate. The solvents, diethyl ether andtetrahydrofuran, were removed under vacuum to yield an oily productcontaining 1,1-bis(4-methoxyphenyl)-2-propyn-1-ol, which was notpurified further but used directly in the next step.

STEP 2

1,1-Bis(4-methoxyphenyl)-2-propyn-1-ol (about 0.025 mole) from Step 1and methyl, 4-hydroxy-6-methoxy-1-methyl-2-naphthoate (5 g, 0,022 mole)were added to a reaction flask containing 200 ml of toluene and stirred.A catalytic amount of p-toluene-sulfonic acid (about 100 milligrams) wasadded, and the mixture was stirred for 4 hours. Afterwards, the reactionmixture was poured into a 10 weight percent sodium hydroxide solution.The organic layer was separated, washed with water, and dried overanhydrous sodium sulfate. The remaining solvent, toluene, was removedunder vacuum. The resulting oil was purified using a silica gel columnand a 1:3 mixture of chloroform:hexane as the eluant. The photochromicfractions were combined and the eluent was removed under vacuum. Theresulting product was induced to crystallize from hexane. The recoveredproduct had a melting point of 132°-133° C. A nuclear magnetic resonance(NMR) spectrum showed the product to have a structure consistent with2,2-bis(4-methoxyphenyl)-5-methoxycarbonyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran.

STEP 3

2,2-Bis(4-methoxyphenyl)-5-methoxycarbonyl-6-methyl-9-methoxy-[2H]-naphtho[1,2-b]pyran(1.7 g, 0.0034 mole) from Step 2 was dissolved in a reaction flaskcontaining 200 ml of tetrahydrofuran and stirred. Lithium aluminumhydride (0.13 g, 0.0034 mole) was carefully added and the mixture wasstirred for 2 hours at room temperature. 2-Propanol was added followedby the addition of a 5 weight percent aqueous hydrochloric acidsolution. The resulting mixture was extracted with two 100 ml portionsof methylene chloride. The organic extracts were combined and dried overmagnesium sulfate. The solvent, methylene chloride, was removed undervacuum. The product was induced to crystallize from diethyl ether andthe crystals were collected by suction filtration. The recoveredproduct, 1.0 g, had a melting point of 125°-127° C. A nuclear magneticresonance (NMR) spectrum showed the product to have a structureconsistent with2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran.

EXAMPLE 2 STEP 1

Potassium t-butoxide (75 grams(g), 0.75 mole) was added to a reactionflask containing 200 milliliters (ml) of toluene. The resulting slurrywas heated to reflux temperature under a nitrogen atmosphere while amixture of benzophenone (91 g, 0.5 mole), dimethyl succinate (90 g, 0.62mole) and toluene (100 g) was added over a period of 30 minutes. Afterthe addition, the resulting pasty mixture was maintained at refluxtemperature for two hours and then cooled to room temperature. About 400ml of water was added and the mixture was stirred for 30 minutes. Theaqueous layer was separated, acidified with dilute hydrochloric acid,and extracted with 200 ml of toluene. The solvent was removed undervacuum yielding a viscous oil that later solidified, which contained theproduct, 4,4-diphenyl-3-methoxycarbonyl-3-butenoic acid. This materialwas not purified further but was used directly in the next step.

STEP 2

The product of Step 1 was dissolved in a reaction flask containing 200ml of toluene. Acetic anhydride (100 g) and anhydrous sodium acetate (15g) were added to the reaction flask and the mixture was refluxed for 17hours. The resulting mixture was cooled to room temperature and thesolvent was removed under vacuum. Methylene chloride (200 ml) was addedto the reaction flask containing the resulting residue. Water (200 ml)was added to the reaction flask followed by the slow addition of solidsodium carbonate until the evolution of carbon dioxide ceased. Themethylene chloride layer was separated, washed with water, and thesolvent was removed under vacuum to yield a viscous oil containing1-acetoxy-3-methoxycarbonyl-4-phenylnaphthalene.

STEP 3

Methanol (400 ml) was added to the reaction flask containing1-acetoxy-3-methoxycarbonyl-4-phenylnaphthalene from Step 2.Hydrochloric acid, concentrated (2 ml) was added to the reaction flaskand the resulting mixture was heated to reflux temperature. After 4hours, the mixture was cooled to room temperature, the solvent wasremoved under vacuum, and the resulting crystals were collected bysuction filtration. The collected crystals were washed with methanol andair dried. The recovered product, 100 g, had a melting point of174°-176° C. A nuclear magnetic resonance (NMR) spectrum showed theproduct to have a structure consistent with4-phenyl-3-methoxycarbonyl-1-naphthol.

STEP 4

4-Phenyl-3-methoxycarbonyl-1-naphthol (2 g) from Step 3 and1,1-bis(4-methoxyphenyl)-2-propyn-1-ol (2 g) from Step 1 of Example 1were added to a reaction flask containing 100 ml of toluene and stirred.The resulting mixture was heated to 40° C. and a catalytic amount (a fewdrops) of dodecyl benzenesulfonic acid was added, i.e., an amountsufficient to produce a deep red color in the mixture. After 3 hours ofstirring at 40° C., the mixture was cooled and washed with water. Theorganic layer was separated, and the solvent, toluene was removed undervacuum. The resulting oil was purified using a silica gel column and a2:1 hexane:ethyl acetate mixture as the eluant. The photochromicfractions were collected and the solvent was removed under vacuum. Theresulting product (2.0 g) was crystallized from a hexane-ether mixtureand collected by suction filtration as off-white crystals. The recoveredproduct had a melting point of 168°-169° C. A nuclear magnetic resonance(NMR) spectrum showed the product to have a structure consistent with2,2-bis(4-methoxyphenyl)-5-methoxycarbonyl-6-phenyl-2H-naphtho[1,2-b]pyran.

STEP 5

2,2-Bis(4-methoxyphenyl)-5-methoxycarbonyl-6-phenyl-2H-naphtho[1,2-b]pyran(10.0 g, 0.02 mole) from Step 4 was dissolved in a reaction flaskcontaining 300 ml of tetrahydrofuran. Lithium aluminum hydride (1.2 g,0.032 mole) was carefully added to the stirred solution and the mixtureheated to 40° C. for 2-1/2 hours. After cooling to room temperature,2-propanol was added followed by the addition of a 5 weight percentaqueous hydrochloric acid solution. The resulting mixture was extractedwith three 100 ml portions of diethyl ether. The organic extracts werecombined and dried over magnesium sulfate. The solvent, diethyl ether,was removed under vacuum. The resulting residue was induced tocrystallize from diethyl ether and the crystals were collected bysuction filtration. Three grams of the desired product was recovered. Anuclear magnetic resonance (NMR) spectrum showed the product to have astructure consistent with2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-phenyl-2H-naphtho[1,2-b]pyran.

EXAMPLE 3

2,2-Bis(4-methoxyphenyl)-5-hydroxymethyl-6-phenyl-2H-naphtho[1,2-b]pyran(2.0 g, 0.004 mole) from Step 4 of Example 2, was dissolved in areaction flask containing 200 ml of methylene chloride and 1.2equivalents of triethyl amine. Acetyl chloride (0.37 g, 0.0048 mole) wasadded to the stirred mixture which was heated to reflux temperature for4 hours. After cooling to room temperature, diethyl ether was added andtriethylamine hydrochloride, a byproduct, was removed by filtration. Theresulting product was purified on a silica gel column using chloroformas the eluant. The photochromic fractions were collected and the solventwas removed under vacuum. The recovered product, 0.2 g, was induced tocrystallize from diethyl ether. A nuclear magnetic resonance (NMR)spectrum showed the product to have a structure consistent with2,2-bis(4-methoxyphenyl)-5-acetoxymethyl-6-phenyl-2H-naphtho[1,2-b]pyran.

STEP 1

3-methoxycarbonyl-4-methyl-7-methoxy-1-naphthol (12 g) was added to areaction flask containing potassium hydroxide (25 g), water (250 ml) andethanol (50 ml). The mixture was heated on a steam bath for six hours,cooled to room temperature, and poured into an excess of cold dilute(approximately 5 weight percent) aqueous hydrochloric acid. Theresulting solid product was removed by suction filtration and dried toyield 11 g of the desired product,3-carboxy-4-methyl-7-methoxy-1-naphthol.

STEP 2

3-carboxy-4-methyl-7-methoxy-1-naphthol (11 g) from Step 1 was added toa reaction flask containing 100 ml of methylene chloride. Triethyl amine(10 g, 0.1 mole) was added with stirring. The resulting exothermicreaction mixture was cooled in an ice bath. Acetyl chloride (4 g, 0.05mole) was added dropwise while maintaining the temperature at 5° C. Themixture was stirred an additional 15 minutes at 5° C. and then warmed toroom temperature where it was stirred an additional 15 minutes beforepouring into an excess of cool dilute(approximately 5 weight percent)aqueous hydrochloric acid. The precipitated product was suction filteredfrom the two phase mixture, washed with fresh methylene chloride, anddried to yield 11 g of the desired product. A NMR spectrum showed theproduct to have a structure consistent with1-acetoxy-3-carboxy-4-methyl-7-methoxynaphthalene.

STEP 3

1-acetoxy-3-carboxy-4-methyl-7-methoxynaphthalene (11 g) from Step 2 wasadded to a reaction flask containing 20 ml of thionyl chloride and themixture was heated on a steam bath. After about 30 minutes, when HCIevolution was complete, the excess thionyl chloride was removed on arotary evaporator to yield the acid chloride as a solid. The product,1-acetoxy-3-chlorocarbonyl-4-methyl-7-methoxynaphthalene, was notfurther purified but was used directly in the next step.

STEP 4

One-half of the 1-acetoxy-3-chlorocarbonyl-4-methyl-7-methoxynaphthalenefrom Step 3 was added in small portions to a reaction flask containing amixture of methylene chloride (50 ml), piperidine (4.25 g, 0.05 mole)and triethyl amine (5 g, 0.05 mole). After completing the addition, anexcess of cool dilute (approximately 5 weight percent) aqueoushydrochloric acid was added and the resulting solution was mixed. Theorganic layer was separated, washed successively with water, diluteaqueous sodium carbonate, and water. The solvent, methylene chloride,was removed under vacuum to yield the desired product as an oil. A NMRspectrum showed the product to have a structure consistent with1-acetoxy-3-piperidinocarbonyl-4-methyl-7-methoxynaphthalene.

STEP 5

A mixture (200 ml) of methanol and concentrated hydrochloric acid (2 ml)was added to a reaction flask containing1-acetoxy-3-piperidinocarbonyl-4-methyl-7-methoxynaphthalene from Step4. The resulting reaction mixture was refluxed on a steam bath for 2hours. Afterwards, the mixture was cooled to room temperature and pouredinto dilute aqueous hydrochloric acid. The resulting precipitate wassuction filtered, washed with water, and dried to yield 4.8 g of thedesired product as tan crystals. A NMR spectrum showed the product tohave a structure consistent with3-piperidinocarbonyl-4-methyl-7-methoxy-1-naphthol.

STEP 6

3-piperidinocarbonyl-4-methyl-7-methoxy-1-naphthol (2.5 g) from Step 5and 1-(2,3-dihydrobenzofur-5-yl)-1-(4-methoxyphenyl)-2-propyn-1-ol (2.5g) were added to a reaction flask containing 100 ml of toluene andstirred. The stirred mixture was heated to 50° C. and a few drops ofdodecyl benzenesulfonic acid were added (an amount sufficient to producea deep red color). After two hours, the reaction mixture was cooled toroom temperature and water was added. The organic layer was washed withwater and the solvent was removed on a rotary evaporator. The resultingoil was purified using a silica gel column and a 1:1 hexane:ethylacetate mixture as the eluant. The photochromic fractions were combined,concentrated and induced to crystallize from a small amount of a diethylether:hexane mixture. The desired product was recovered by suctionfiltration and dried to yield 2.6 g of crystals having a melting pointof 201°-203° C. A NMR spectrum showed the product to have a structureconsistent with2-(4-methoxyphenyl)-2-(2,3-dihydrobenzofuran-5-yl)-5-piperidinocarbonyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran.

EXAMPLE 5 PART A

Testing was done with the photochromic naphthopyrans of the Examplesincorporated into polymeric samples by the following method. Thequantity of naphthopyran calculated to yield a 1.5 times 10⁻³ molalsolution was added to a flask containing 50 grams of a monomer blend of4 parts ethoxylated bisphenol A dimethacrylate (BPA 2EO DMA), 1 partpoly(ethylene glycol) 600 dimethacrylate, and 0.033 weight percent2,2'-azobis(2-methyl propionitrile) (AIBN). The naphthopyran wasdissolved into the monomer blend by stirring and gentle heating, ifnecessary. After a clear solution was obtained, it was poured into aflat sheet mold having the interior dimensions of 2.2 mm×6 inches (15.24cm)×6 inches (15.24 cm). The mold was sealed and placed in a horizontalair flow, programmable oven set to increase the temperature from 40° C.to 95° C. over a 5 hour interval, hold the temperature at 95° C. for 3hours and then lower it to 60° C. for at least 2 hours before the end ofthe curing cycle. After the mold was opened, the polymer sheet was cutusing a diamond blade saw into 2 inch (5.1 centimeters) test squares.

Part B

The photochromic test squares prepared in Part A were tested forphotochromic response rates on an optical bench. Prior to testing on theoptical bench, the photochromic test squares were exposed to 365nanometer ultraviolet light for about 15 minutes to activate thephotochromic compounds and then placed into a 76° C. oven for about 15minutes to bleach or inactivate the photochromic compounds. The testsquares were then cooled to room temperature, exposed to fluorescentroom lighting for at least 2 hours and then kept covered for at least 2hours prior to testing on an optical bench maintained at 75° F. (23.9°C.). The bench was fitted with a 150 watt Xenon arc lamp, a remotecontrolled shutter, a copper sulfate bath acting as a heat sink for thearc lamp, a Schott WG-320 nm cut-off filter which removes shortwavelength radiation; neutral density filter(s) and a sample holder inwhich the square to be tested was inserted. A collimated beam of lightfrom a tungsten lamp was passed through the square at a small anglenormal to the square. After passing through the square, the light fromthe tungsten lamp was directed through a photopic filter attached to adetector. The photopic filter passes wavelengths such that the detectormimics the response of the human eye. The output signals from thedetector(s) were processed by a radiometer.

Change in optical density (ΔOD) was determined by inserting a testsquare in the bleached state into the sample holder, adjusting thetransmittance scale to 100%, opening the shutter from the Xenon lamp toprovide ultraviolet radiation to change the test square from thebleached state to an activated (i.e., darkened) state, measuring thetransmittance in the activated state, and calculating the change inoptical density according to the formula Δ OD=log(100/%Ta) where %Ta isthe percent transmittance in the activated state and the logarithm is tothe base 10.

The Δ OD/Min, which represents the sensitivity of the photochromiccompound's response to UV light, was measured over the first five (5)seconds of UV exposure, then expressed on a per minute basis. Thesaturation optical density (OD) was taken under identical conditions asthe Δ OD/Min, except UV exposure was continued for 20 minutes for theexamples in Table 1. The lambda max reported in Table 1 is thewavelength in the visible spectrum at which the maximum absorption ofthe activated (colored) form of the photochromic compound in adiethylene glycol bis(allyl carbonate) composition occurs. The BleachRate (T 1/2) is the time interval in seconds for the absorbance of theactivated form of the naphthopyran in the test squares to reach one halfthe highest absorbance at room temperature (75° F., 23.9° C.) afterremoval of the source of activating light. Results for the Compounds ofthe Examples are tabulated in Table 1.

                  TABLE 1                                                         ______________________________________                                                 LAMBDA    ΔOD/MIN                                              EXAMPLE  MAX       SENSI-    ΔOD@                                                                             Bleach                                  COMPOUNDS                                                                              (VISIBLE) TIVITY    SATURATION                                                                             (T1/2)                                  ______________________________________                                        1        520       0.38      0.42     303 sec                                 2        506       0.32      0.26     149 sec                                 3        508       0.33      0.25     109 sec                                 4        535       0.34      0.65     >800 sec                                ______________________________________                                    

The results of Table 1 show that the bleach rate of2H-naphtho[1,2-b]pyrans is dramatically effected by the nature of the5-position substituent. For example, Compounds 1 through 3 have anacceptable bleach rate, i.e., fade rate, while Compound 4 fades muchslower. All 4 of the Example Compounds have a high OD at saturation,i.e., activated intensity, and a high coloration rate, i.e.,sensitivity.

Although the present invention has been described with reference to thespecific details of particular embodiments thereof, it is not intendedthat such details be regarded as limitations upon the scope of theinvention except as and to the extent that they are included in theaccompanying claims.

We claim:
 1. A naphthopyran compound represented by the followinggraphic formula: ##STR11## wherein, (a) R₁ is selected from the groupconsisting of --CH₂ X and --C(O)Y, wherein X is halogen, hydroxy,benzoyloxy, C₁ -C₆ alkoxy, C₂ -C₆ acyloxy, amino, C₁ -C₆mono-alkylamino, C₁ -C₆ dialkylamino, morpholino, piperidino,1-indolinyl, pyrrolidyl, trimethylsilyloxy, or the group, --OCH(R₁₁)Z, Yis the group, --OCH(R₁₁)Z, or an unsubstituted, mono-substituted, ordi-substituted heterocyclic ring selected from the group consisting of1-indolinyl, morpholino, piperidino, 1-pyrrolidyl, 1-imidazolidyl,2-imidazolin-1-yl, pyrazolidyl, pyrazolinyl and 1-piperazinyl, wherein Zis --CN, --CF₃, halogen, --C(O)R₁₂, or --COOR₁₂, R₁₁ and R₁₂ arehydrogen or C₁ -C₆ alkyl; said heterocyclic ring substituents beingselected from C₁ -C₆ alkyl and C₁ -C₆ alkoxy, and said halogen beingchloro or fluoro;(b) R₂ and each R₃ are hydrogen, C₁ -C₆ alkyl, C₃ -C₇cycloalkyl, unsubstituted, mono-, di-, or tri-substituted phenyl, thegroup, --OR₆, wherein R₆ is hydrogen, (C₁ -C₆)alkyl, phenyl(C₁-C₃)alkyl, mono-substituted phenyl(C₁ -C₃)alkyl, (C₁ -C₆)alkoxy(C₂-C₄)alkyl, C₃ -C₇ cycloalkyl, mono(C₁ -C₄)alkyl substituted C₃ -C₇cycloalkyl, C₁ -C₆ haloalkyl, allyl, the group, --CH(R₇)W, wherein W is--CN, --CF₃, halogen, --C(O)R₇, or --COOR₇, wherein R₇ is hydrogen, C₁-C₆ alkyl, or (C₁ -C₆)alkoxy(C₂ -C₄)alkyl, or R₆ is the group, --C(O)T,wherein T is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, the substituted orunsubstituted aryl groups phenyl or naphthyl, phenoxy, C₁ -C₆ mono-ordi-alkyl substituted phenoxy, C₁ -C₆ mono-or di-alkoxy substitutedphenoxy, each of said phenyl or naphthyl substituents being C₁ -C₆alkyl, C₁ -C₆ alkoxy or halogen, each of said halogen or halosubstituents being chloro or fluoro and n is selected from the integers0, 1, 2, and 3; and (c) B and B' are each selected from the groupconsisting of:(i) the unsubstituted, mono-, di-, and tri-substitutedaryl groups phenyl and naphthyl; (ii) the unsubstituted, mono- anddi-substituted heterocyclic aromatic groups pyridyl, furanyl,benzofuran-2-yl, benzofuran-3-yl, thienyl, benzothien-2-yl,benzothien-3-yl, dibenzothienyl, dibenzofuranyl, and carbazolyl, saidaryl and heterocyclic substituents being selected from the groupconsisting of hydroxy, amino, C₁ -C₆ monoalkylamino, C₁ -C₆dialkylamino, morpholino, piperidino, 1-indolinyl, pyrrolidyl,1-imidazolidyl, 2-imidazolin-1-yl, 2-pyrazolidyl, pyrazolinyl,1-piperazinyl, C₁ -C₆ alkyl, C₁ -C₆ haloalkyl, C₁ -C₆ alkoxy, mono(C₁-C₆)alkoxy(C₁ -C₄)alkyl, acryloxy, methacryloxy, and halogen, saidhalogen or (halo) group being fluoro or chloro; (iii) the groupsrepresented by the following graphic formulae: ##STR12## wherein D iscarbon or oxygen and E is oxygen or substituted nitrogen, provided thatwhen E is substituted nitrogen, D is carbon, said nitrogen substituentbeing selected from the group consisting of hydrogen, C₁ -C₆ alkyl, andC₂ -C₆ acyl; each R₈ is C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, chloro orfluoro; R₉ and R₁₀ are each hydrogen or C₁ -C₆ alkyl; and m is theinteger 0, 1, or 2; (iv) C₁ -C₆ alkyl, C₁ -C₆ haloalkyl, C₁ -C₆alkoxy(C₁ -C₄)alkyl, C₃ -C₆ cycloalkyl, mono(C₁ -C₆) alkoxy(C₃-C₆)cycloalkyl, mono(C₁ -C₆)alkyl(C₃ -C₆)cycloalkyl, and halo(C₃-C₆)cycloalkyl, said halo groups being fluoro or chloro; and (v) thegroup represented by the following graphic formula: ##STR13## wherein Uis hydrogen or C₁ -C₄ alkyl, and V is selected from the unsubstituted,mono-, and di-substituted members of the group consisting of naphthyl,phenyl, furanyl, and thienyl, wherein the substituents for each memberof said group are C₁ -C₄ alkyl, C₁ -C₄ alkoxy, fluoro, or chloro; or(vi) B and B' taken together form an unsubstituted, mono-, ordi-substituted fluoren-9-ylidene or a member selected from the groupconsisting of saturated C₃ -C₁₂ spiro-monocyclic hydrocarbon rings,saturated C₇ -C₁₂ spiro-bicyclic hydrocarbon rings, and saturated C₇-C₁₂ spiro-tricyclic hydrocarbon rings, said fluoren-9-ylidenesubstituents being selected from the group consisting of C₂ -C₄ alkyl,C₁ -C₄ alkoxy, fluoro and chloro.
 2. The naphthopyran of claim 1wherein:(a) R₁ is selected from the group consisting of --CH₂ X and--C(O)Y, wherein X is hydroxy, C₁ -C₄ alkoxy, or C₂ -C₄ acyloxy, Y isthe group, --OCH(R₁₁)Z, or an unsubstituted or mono-substitutedheterocyclic ring selected from the group consisting of 1-indolinyl,morpholino, piperidino, and 1-pyrrolidyl, wherein Z is --CN, --C(O)R₁₂,or --COOR₁₂, R₁₁ and R₁₂ are hydrogen or C₁ -C₄ alkyl; said heterocyclicring substituents being selected from C₁ -C₄ alkyl and C₁ -C₄ alkoxy;(b) R₂ and each R₃ are hydrogen, C₁ -C₄ alkyl, unsubstituted, mono-,di-, or tri-substituted phenyl, the group, --OR₆, wherein R₆ is C₁ -C₄alkyl or the group, CH(R₇)W, wherein W is --COOR₇, and R₇ is hydrogen orC₁ -C₄ alkyl, said phenyl substituents being C₁ -C₄ alkyl, C₁ -C₄ alkoxyor fluoro and n is selected from the integers 0, 1, and 2; and (c) B andB' are each selected from the group consisting of:(i) unsubstituted,mono-, di-, and tri-substituted phenyl; (ii) the unsubstituted, mono-and di-substituted heterocyclic aromatic groups pyridyl, furanyl,benzofuran-2-yl, benzofuran-3-yl, thienyl, benzothien-2-yl,benzothien-3-yl, dibenzothienyl, dibenzofuranyl, and carbazolyl, each ofsaid phenyl and heterocyclic substituents being selected from the groupconsisting of morpholino, piperidino, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, andhalogen, said halogen or (halo) group being fluoro or chloro; (iii) thegroups represented by the following graphic formula: ##STR14## wherein Dis carbon and E is oxygen; each R₈ is C₁ -C₄ alkyl, C₁ -C₄ alkoxy,hydroxy, or halogen, said halogen being chloro or fluoro; R₉ and R₁₀ areeach hydrogen or C₁ -C₄ alkyl; and m is the integer 0, 1, or 2; (iv) C₁-C₄ alkyl, C₁ -C₆ alkoxy(C₁ -C₄)alkyl, and C₃ -C₆ cycloalkyl; and (v)the group represented by the following graphic formula: ##STR15##wherein U is hydrogen or methyl, and V is phenyl or mono-substitutedphenyl, said phenyl substituent being C₁ -C₄ alkyl, C₁ -C₄ alkoxy, orfluoro; or (vi) B and B' taken together form an unsubstituted ormono-substituted fluoren-9-ylidene or a member selected from the groupconsisting of saturated C₃ -C₈ spiro-monocyclic hydrocarbon rings,saturated C₇ -C₁₀ spiro-bicyclic hydrocarbon rings, and saturated C₇-C₁₀ spiro-tricyclic hydrocarbon rings.
 3. The naphthopyran of claim 2wherein:(a) R₁ is the group, --CH₂ X, or --C(O)Y, wherein X is hydroxy,C₁ -C₄ alkoxy, or C₂ -C₄ acyloxy and Y is an unsubstituted ormono-substituted heterocyclic ring selected from the group consisting of1-indolinyl, morpholino, and piperidino; (b) R₂ and each R₃ arehydrogen, C₁ -C₂ alkyl, unsubstituted, mono-, di-, or tri-substitutedphenyl, the group, --OR₆, wherein R₆ is C₁ -C₂ alkyl or the group,--CH(R₇)W, wherein W is --COOR₇, and R₇ is C₁ -C₂ alkyl, said phenylsubstituents being C₁ -C₂ alkyl, C₁ -C₂ alkoxy or fluoro, and n isselected from the integers 0, 1, and 2; and (c) B and B' are eachselected from the group consisting of:(i) unsubstituted, mono-, anddi-substituted phenyl; (ii) the unsubstituted, mono- and di-substitutedheterocyclic aromatic groups pyridyl, benzofuran-2-yl, benzothien-2-yl,dibenzothienyl, and dibenzofuranyl, each of said phenyl and heterocyclicsubstituents being selected from the group consisting of morpholino,piperidino, C₁ -C₂ alkyl, and C₁ -C₂ alkoxy; and (iii) the groupsrepresented by the following graphic formula: ##STR16## wherein D iscarbon and E is oxygen; each R₈ is C₁ -C₂ alkyl, C₁ -C₂ alkoxy orfluoro; R₉ and R₁₀ are each hydrogen or C₁ -C₂ alkyl; and m is theinteger 0, 1, or 2; or (iv) B and B' taken together formfluoren-9-ylidene, bornylidene, norbornylidene,bicyclo[3.3.1]nonan-9-ylidene or adamantylidene.
 4. The naphthopyran ofclaim 3 wherein R₁ is hydroxymethyl, acetoxymethyl, morpholinocarbonyl,or piperidinocarbonyl; R₂ and each R₃ are hydrogen, phenyl, methoxy, ormethyl; and B and B' are each phenyl, methoxy substituted phenyl,morpholino substituted phenyl, dibenzofuran-2-yl, or2,3-dihydrobenzofuran-5-yl.
 5. A naphthopyran compound selected from thegroup consisting of:(a) 2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran; (b) 2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-phenyl-2H-naphtho[1,2-b]pyran; (c)2,2-bis (4-methoxyphenyl)-5-acetoxymethyl-6-phenyl-2H-naphtho[1,2-b]pyran; (d)2-(4-methoxyphenyl)-2-(2,3-dihydrobenzofuran-5-yl)-5-piperidinocarbonyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran;(e)2,2-bis(4-methoxyphenyl)-5-hydroxymethyl-6-methoxy-2H-naphtho[1,2-b]pyran;(f) 2,2-diphenyl-5-methoxymethyl-6-methoxy-2H-naphtho[1,2-b]pyran; (g)2,2-spiroadamantylene-5-acetoxymethyl-6-methoxy-2H-naphtho[1,2-b]pyran;(h)2,2-bis(4-methoxyphenyl)-5-trimethylsilyloxymethyl-6-methoxy-2H-naphtho[1,2-b]pyran;(i)2-(4-methoxyphenyl)-2-t-butyl-5-methoxymethyl-6-phenyl-9-methoxy-2H-naphtho[1,2-b]pyran;and (j)2-(4-methoxyphenyl)-2-(2,3-dihydrobenzofuran-5-yl)-5-chloromethyl-6-methyl-9-methoxy-2H-naphtho[1,2-b]pyran.6. A photochromic article comprising a polymeric organic host materialand a photochromic amount of a naphthopyran compound of claim
 1. 7. Thephotochromic article of claim 6 wherein the polymeric organic hostmaterial is selected from the group consisting of polyacrylates,polymethacrylates, poly( C₁ -C₁₂ alkyl methacrylates), polyoxy(alkylenemethacrylates), poly (alkoxylated phenol methacrylates), celluloseacetate, cellulose triacetate, cellulose acetate propionate, celluloseacetate butyrate, poly(vinyl acetate), poly(vinyl alcohol), poly(vinylchloride), poly(vinylidene chloride), thermoplastic polycarbonates,polyesters, polyurethanes, poly(ethylene terephthalate), polystyrene,poly(alpha methylstyrene), copoly(styrene-methylmethacrylate),copoly(styrene-acrylonitrile), polyvinylbutyral and polymers of membersof the group consisting of polyol(allyl carbonate) monomers,polyfunctional acrylate monomers, polyfunctional methacrylate monomers,diethylene glycol dimethacrylate monomers, diisopropenyl benzenemonomers, alkoxylated polyhydric alcohol acrylate monomers anddiallylidene pentaerythritol monomers.
 8. A photochromic articlecomprising a polymeric organic host material and a photochromic amountof a naphthopyran compound of claim
 2. 9. The photochromic article ofclaim 8 wherein the polymeric organic host material is selected from thegroup consisting of polyacrylates, polymethacrylates, poly( C₁ -C₁₂alkyl methacrylates), polyoxy(alkylene methacrylates), poly (alkoxylatedphenol methacrylates), cellulose acetate, cellulose triacetate,cellulose acetate propionate, cellulose acetate butyrate, poly(vinylacetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidenechloride), thermoplastic polycarbonates, polyesters, polyurethanes,poly(ethylene terephthalate), polystyrene, poly(alpha methylstyrene),copoly(styrene-methylmethacrylate), copoly(styrene-acrylonitrile),polyvinylbutyral and polymers of members of the group consisting ofpolyol(allyl carbonate) monomers, polyfunctional acrylate monomers,polyfunctional methacrylate monomers, diethylene glycol dimethacrylatemonomers, diisopropenyl benzene monomers, alkoxylated polyhydric alcoholacrylate monomers and diallylidene pentaerythritol monomers.
 10. Thephotochromic article of claim 9 wherein the polymeric organic hostmaterial is a solid transparent homopolymer or copolymer selected fromthe group consisting of poly(methyl methacrylate), poly(ethylene glycolbis methacrylate), poly(ethoxylated bisphenol A dimethacrylate),thermoplastic polycarbonate, poly(vinyl acetate), polyvinylbutyral,polyurethane and polymers of members of the group consisting ofdiethylene glycol bis(allyl carbonate) monomers, diethylene glycoldimethacrylate monomers, diisopropenyl benzene monomers, and ethoxylatedtrimethylol propane triacrylate monomers.
 11. The photochromic articleof claim 10 wherein the photochromic compound is present in an amount offrom about 0.05 to 1.0 milligram per square centimeter of organic hostmaterial surface to which the photochromic substance(s) is incorporatedor applied.
 12. The photochromic article of claim 11 wherein the articleis a lens.
 13. A photochromic article comprising a photochromic amountof the naphthopyran compound of claim 3 and a polymeric organic hostmaterial selected from the group consisting of poly(methylmethacrylate), poly(ethylene glycol bis methacrylate), poly(ethoxylatedbisphenol A dimethacrylate), thermoplastic polycarbonate, poly(vinylacetate), polyvinylbutyral, polyurethane and polymers of members of thegroup consisting of diethylene glycol bis(allyl carbonate) monomers,diethylene glycol dimethacrylate monomers, diisopropenyl benzenemonomers, and ethoxylated trimethylol propane triacrylate monomers. 14.A photochromic article comprising a photochromic amount of thenaphthopyran compound of claim 4 and a polymeric organic host materialselected from the group consisting of poly(methyl methacrylate),poly(ethylene glycol bis methacrylate), poly(ethoxylated hisphenol Adimethacrylate), thermoplastic polycarbonate, poly(vinyl acetate),polyvinylbutyral, polyurethane and polymers of members of the groupconsisting of diethylene glycol bis(allyl carbonate) monomers,diethylene glycol dimethacrylate monomers, diisopropenyl benzenemonomers, and ethoxylated trimethylol propane triacrylate monomers. 15.A photochromic article comprising, in combination, a solid transparentpolymeric organic host material, and a photochromic amount of each of(a) at least one naphthopyran compound of claim 1, and (b) at least oneother organic photochromic compound having at least one activatedabsorption maxima within the range of between about 400 and 700nanometers.
 16. The photochromic article of claim 15 wherein thepolymeric organic host material is selected from the group consisting ofpolyacrylates, polymethacrylates, poly( C₁ -C₁₂ alkyl methacrylates),polyoxy(alkylene methacrylates), poly (alkoxylated phenolmethacrylates), cellulose acetate, cellulose triacetate, celluloseacetate propionate, cellulose acetate butyrate, poly(vinyl acetate),poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride),thermoplastic polycarbonates, polyesters, polyurethanes, poly(ethyleneterephthalate), polystyrene, poly(alpha methylstyrene),copoly(styrene-methylmethacrylate), copoly(styrene-acrylonitrile),polyvinylbutyral and polymers of members of the group consisting ofpolyol(allyl carbonate) monomers, polyfunctional acrylate monomers,polyfunctional methacrylate monomers, diethylene glycol dimethacrylatemonomers, diisopropenyl benzene monomers, alkoxylated polyhydric alcoholacrylate monomers and diallylidene pentaerythritol monomers.
 17. Thephotochromic article of claim 15 wherein the organic photochromiccompound (b) is selected from the group consisting of:(a) organicphotochromic substances having at least one absorption maximum in thevisible range of between 400 and less than 500 nanometers; (b) organicphotochromic substances having an absorption maximum within the visiblerange of between about 400 and 500 nanometers and an absorption maximumwithin the visible range of between 500 and 700 nanometers; and (c)organic photochromic substances having an activated absorption maxima inthe visible range of greater than 570 nanometers; and (d) mixtures ofsaid organic photochromic substances.
 18. The photochromic article ofclaim 17 wherein the organic photochromic compound (b) is an organicphotochromic substances having an activated absorption maxima in thevisible range of greater than 570 nanometers.
 19. The photochromicarticle of claim 16 wherein the polymeric organic host material is asolid transparent homopolymer or copolymer selected from the groupconsisting of poly(methyl methacrylate), poly(ethylene glycol bismethacrylate), poly(ethoxylated bisphenol A dimethacrylate),thermoplastic polycarbonate, poly(vinyl acetate), polyvinylbutyral,polyurethane and polymers of members of the group consisting ofdiethylene glycol bis(allyl carbonate) monomers, diethylene glycoldimethacrylate monomers, diisopropenyl benzene monomers, and ethoxylatedtrimethylol propane triacrylate monomers.
 20. The photochromic articleof claim 17 wherein the organic photochromic compound (b) is selectedfrom the group consisting of spiro(indoline)naphthoxazines,spiro(indoline)-pyridobenzoxazines,spiro(benzindoline)pyridobenzoxazines,spiro(benzindoline)naphthoxazines, spiro(benzindoline)naphthopyrans,spiro(indoline)benzoxazines, spiro(indoline)benzopyrans,spiro(indoline)naphthopyrans, spiro(indoline)quinopyrans,spiro(indoline)pyrans, 3H -naphtho[2,1-b]pyrans,2H-phenanthro[4,3-b]pyrans; 3H -phenanthro[1,2-b]pyrans; benzopyrancompounds and mixtures of such photochromic substances.
 21. Thenaphthopyran of claim 2 wherein:(a) R₁ is the group --C(O)Y, wherein Yis the group, --OCH(R₁₁)Z, wherein R₁₁ is hydrogen and Z is --COOR₁₂,wherein R₁₂ is C₁ -C₄ alkyl; (b) R₂ is hydrogen; (c) R₃ is C₁ -C₄ alkyl,n is 1; and (d) B and B' are each phenyl.
 22. The naphthopyran of claim21 wherein R₃ is C₁ -C₂ alkyl.
 23. The naphthopyran of claim 22 whereinR₃ is methyl.
 24. A photochromic article comprising a polymeric organichost material and a photochromic amount of a naphthopyran compound ofclaim
 21. 25. A photochromic article comprising a polymeric organic hostmaterial and a photochromic amount of a naphthopyran compound of claim22.